add missing javax.servlet-api to IzPack installer configuration
add missing javax.servlet-api to IzPack installer configuration

caiyingyuan/tigase71,caiyingyuan/tigase71,amikey/tigase-server,amikey/tigase-server,caiyingyuan/tigase71,amikey/tigase-server,amikey/tigase-server,amikey/tigase-server,caiyingyuan/tigase71,caiyingyuan/tigase71,amikey/tigase-server,caiyingyuan/tigase71